USN-3548-2: Linux kernel (HWE) vulnerability

Ubuntu Security Notice USN-3548-2

26th January, 2018

linux-hwe, linux-azure, linux-gcp, linux-oem vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS

Summary

The system could be made to crash or run programs as an administrator.

Software description

  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-oem - Linux kernel for OEM processors

Details

USN-3548-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.10.
This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu
16.04 LTS.

Jay Vosburgh discovered a logic error in the x86-64 syscall entry
implementation in the Linux kernel, introduced as part of the
mitigations for the Spectre vulnerability. A local attacker could use
this to cause a denial of service or possibly execute arbitrary code.

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 16.04 LTS:
linux-image-gke 4.13.0.1008.10
linux-image-gcp 4.13.0.1008.10
linux-image-generic-hwe-16.04 4.13.0.32.52
linux-image-4.13.0-1007-azure 4.13.0-1007.9
linux-image-4.13.0-32-lowlatency 4.13.0-32.35~16.04.1
linux-image-4.13.0-1008-gcp 4.13.0-1008.11
linux-image-lowlatency-hwe-16.04 4.13.0.32.52
linux-image-4.13.0-32-generic 4.13.0-32.35~16.04.1
linux-image-oem 4.13.0.1019.23
linux-image-4.13.0-1019-oem 4.13.0-1019.20
linux-image-azure 4.13.0.1007.8

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

LP: 1745564